Faulty thread indicator for sewing machines, etc.



Dec. 19, 1950 A. E. STEVENS FAULTY THREAD INDICATOR FOR SEWING MACHINES, ETC

2 Sheets-Sheet 1 Filed March 11, 1948 INVENTOR. fiusljz'n ZT-Sleven I97'TOIPNEK Dec. 19, 1950 s v s 2,534,999

FAULTY THREAD INDICATOR FOR SEWING MACHINES, ETC Filed March 11, 1948 2 Sheets-Sheef- '2 65 l 5 JJ 1 532 v; 43 4/ :2 flusljm ESZ'euens 62- w a a BY Patented Dec. 19, 1950 UNITED STATES PATENT OFFECE FAULTY THREAD INDICATOR FOR SEWING MACHINES, ETC.

3 Claims.

My invention relates to improvements in faulty thread indicators for textile machinery and it has particular reference to sewing machines although not limited to use in connection with same.

In practice the device may operate in various ways to indicate the presence of knots, slubs, or other imperfections in the thread being fed to sewing machine needles or other instrumentalities. For instance, it may operate the stop motion of the machine, operate a visual or audible signal, or it may function to perform both of these ofiices.

As is well known to those who are conversant with the sewing machine and kindred arts, the primary cause of thread breakage is the presence of slubs, knots, or other bulge formations in the thread which cause same to break when the needle is reached. Such imperfections frequently result in the breaking of machine needles, damage to needle plates, loopers, hooks and other sewing machine parts. But even when a thread break occurs without damage to machine parts, a substantial slow-down in production results because it is necessary for the machine operator to remove the material from the machine and re-sew it. And frequently a substantial length of material will pass through a machine after a thread has broken without the fact being noticed,

and sometimes the absence of stitching at certain points in a garment, for instance, won't be discovered until the finished item is checked by an inspector prior to shipment.

It is therefore the primary object of my invention to provide a device which will instantly apprise the operator of the sewing machine or other textile machine of the presence of a thread defect before the thread reaches the needle or other thread-manipulating element to the end that shut-downs due to machine part breakage will be eliminated and defective work avoided.

More specifically, the invention contemplates a device for the purpose specified which is very simple in construction, highly efiicient in practical use, and which will be unaffected by lint, oil, corrosion, dirt, or dust.

Still another object of the invention is to provide a faulty thread detector or the like which is very compact and of small size so as to take up very little space and which further embodies novel mounting means which enables the unit to be readily attached to a thread stand or other object above the top of a sewing machine, for instance, so as to leave all of the machine top and, for that matter, the top of the machinesupporting bench, free for use by the operator. The novel mounting phase of the invention will, as will be obvious, greatly lessen the likelihood of thread breakage by a careless operator or one who does not coordinate well.

The invention also resides in certain novel features of construction, combination and arrangement of the various parts including a removable casing closure or section which can be detached to admit of inspection of interior parts without dismounting the unit from its support, or for that matter, without necessitating stoppage of the machine with which the unit is associated.

The preferred embodiment of my inventive concept, which is illustrated in the accompanying drawings, functions by electrical circuit control but it is to be understood that this is not an absolute prerequisite. Various changes and modifications may be made in the device as illustrated without departing from the spirit and scope of the invention as claimed hereinafter.

In the drawings, wherein the same reference characters have been used to designate the same parts throughout the several views,

Fig. 1 is a fragmentary perspective view of one end of a familiar type of commercial sewing machine and showing a portion of the thread stand which is associated with the machine;

Fig. 2 is a side elevational view of my faulty thread indicator, a portion of the central post of the thread stand being indicated in dotted lines;

Fig. 3 is a front elevational view of the device;

Fig. 4 is a vertical sectional view taken on the line 4-4 of Fig. 2;

' Fig. 5 is another vertical sectional view but taken on the line 5-5 of Fig. 2;

Fig. 6 is a side elevational view looking into the mechanism compartment of the device, the

cover or closure section having been removed;

Fig. 7 is a side elevational view looking into the chamber or recess providing side of the casing cover; and

Fig. 8 is a wiring diagram.

Referring to the drawings by reference characters and turning to Fig. 1, numeral ll! designates a portion of the frame of a conventional commercial sewing machine while H designates the conventional frictional guide through which the threads or ends I2 pass in their travel from the thread packages or bobbins E3 to the sewing machine needles (not shown).

The thread packages l3 are carried as usual on the cone-like cores I4 which are rotatably mounted on the vertical bearing posts [5 which extend upwardly from the sockets |5a adjacent the outer ends of the respective arms l6 of the Web I! which is adjustably carried by the central supporting shaft l8. The central shaft I8 of the thread stand will be supported as usual, as for instance on the top of the bench on which the sewing machine I6 is mounted.

My novel faulty thread indicator unit is generally designated by reference character I9 and it comprehends the mechanism mounting casing section whose open side is adapted to be closed by the closure section 2| which is illustrated in Figs. 4, 5 and '7.

As indicated in Fig. 1, but better shown in Figs. 2 and 6, the mechanism-containing casing section 20 has secured to its bottom 20a the inner end of the mounting bracket 22, whose inner terminal is bent upwardly. as indicated at 22a, to make flat or substantially flat contact with the front wall 28 of the mechanism-containing casing section 20.

Fig. 1 also illustrates the bracket 22 as being adapted to be clamped to the central post iii of the thread stand. In carrying out this phase of the invention it will be noted that the bracket 22 is given a right angle twist as at 23 rearwardly of the unit l9 so as to provide the vertical strap portion 24 whose free end is formed with the stand post-embracing clamp 25.

Figs. 2 and 6 indicate that the clamp 25 is gripped about the thread stand column or post l8 by means of a bolt 26 and nut 21. Thus, the indicator unit |9 can be adjusted to any desired elevation on the central post or column l8 of the thread stand, and likewise can be given desired partial lateral adjustment about said post |8 as an axis so as to provide, as indicated in Fig. 1, for the direct supply of threads or ends |2 from the packages l3 to the friction guide elements II.

It is to be understood that the threads or ends .|2 are carried upwardly from the packages l3 and passed through suitable guides from which said threads or ends are led downwardly, as shown, for passage through portions of my indicator.

Referring again to the indicator unit l9, per se, and turning to Figs. 2, 3, 4, 5, and 6, it will be observed that the mechanism-carrying casing section 20 has the front wall 28, rear wall 29, top a wall 38 and outer side wall 3|, in addition to the bottom wall 20a, previously mentioned. The casing closure section 2| (see Fig. '7) has the front wall 32, the rear wall and top wall 34, in addition to the bottom wall 2|a.

Figs. 4 and 5 clearly indicate that the closure section 2| of the casing is adapted to be inserted into the mechanism-carrying casing section so that corresponding walls of the casing sections 20, 2| make contiguous engagement with one another. that is, of course, except as to the outer side wall of the closure section 2| and the outer side wall 3| of the mechanism-containing casing section 20. These walls are spaced from one another, as indicated in Figs. 4 and 5.

The means for securing the casin sections 2E2 and 2| in assembly includes a nut 36 welded or otherwise secured to the inner surface of the front wall 32 of the closure section 2| at a point adjacent the top wall 34 thereof and in alignment with a hole through the said front wall 32 of said closure section 2| so as to receive the shank 38a of a clamp screw having an external head 38.

When casing sections 2| and 29are assembled, the shank 38a of the clamp screw is adapted to be received in the slot 44 in the front wall 28 of the mechanism-mounting casing section 2 3, as indicated in Fig. 3. When the screw 38a is tightened, its head clamps upon the surface of the front wall 28 of easing section 26.

The counterpart of the nut and screw clamp 38, 38 is provided in the rear wall 33 of the closure section 2| adjacent the bottom wall Zia thereof. Here the nut 39 is welded as at 4?} to the inner surface of said rear wall 33 and receives the shank 4 l a of a screw havin the clamping head 4| which latter is adapted to bear against the outer surface of the rear wall 29 of the mechanism-containing casing section 2:) adjacent the bottom wall 20a thereof, the shank 4|a of the clamp screw being received in an edge slot 43 in th rear wall 29 of said casing section 28, as indicated in Figs. 2 and 6.

Fig. 6 illustrates the inner surface of the outer side wall 3| of casing section 25 as having a cleatlike keeper 42. This keeper 42 is employed for circuit wires 6!, 52, to be hereinafter referred to, so that said wires 6|, 62 will not interfere with the operation of the switch-carrying shaft 55, also to be referred to later on herein. For the sake of clarity, cleat 42 has been deleted in Fig. 4.

The operative relation of my unit l9 to the thread or ends 52 will now be described, reference being had to Figs. 1 and 6 which show the rear wall of the mechanism-containing casing section 20 as having secured thereto the upstanding thread guide 45 while the front wall 28 of said section 28 ha the upstanding thread uide 46. These uides 45 and 46 are provided with thread passage apertures 45b, 46b, respectively; and there will be a number of apertures equal to the number of threads being employed, the apertures being arranged in spaced horizontal series, as shown.

The upper or head portions of the guide 45, 46, which are spaced above the plane of the top of the casing l9, will preferably extend substantially the full width of said casing |5l so as to provide plenty of room for a number of laterally spaced thread guide holes or apertures 45b, 4612, as the case may be. Each of the thread uides 45, 46 has a narrow downwardly-extending attaching portion, these attaching portions being indicated in Fig. 6 by reference characters 45a, 46a, respectively. Screw and nut fasteners 41 are availed of in the illustrated example of the invention for securing the thread guides 45, 46 to the rear and front walls 29, 28, respectively, of the mechanism-containing casing 22.

Next to be dealt with is the thread-actuated, or thread feeler, element 48, the operative arrangement of which in respect to the thread guides 45, 45 is best illustrated in Fig. 1 wherein it is noted that the feeler takes the form of an upwardly and forwardly inclined plate having its top formed with a laterally spaced series of thread-receiving slots opening downwardly from flared entrance openings 49, the slots being indicated by reference character 49a. Each thread slot in the feeler 48 is aligned with corresponding thread guide holes 45?), 46b of the guides 45, 46.

The feeler plate 48 has the bottom bearing curl 50 which tightl embraces the horizontal arm 5| whose inner end outwardly of the closed side wall 3| of the mechanism-containing casing section 23 is bent downwardly parallel therewith and terminates in the bearing disc 53 which is secured on the outer end of the shaft 55.

The bearing 53 at the inner end of the arm 52 like has been indicated, it will frequently be possible to get the knot or other thread imperfection through the needle and into the work without breaking the thread. This would be accomplished in most cases by re-starting the machine and running it slowly until the knot had passed the needle.

Referring to the wiring diagram (Fig. 8) reference character it indicates a generator or other source of power which is grounded as at H at one side and has the circuit wire 12 leading from the other side. The wire 12 connects in series the stop motion operator (which, in the present instance, takes the form of a solenoid magnet 73) and a signal lamp 14 This wire 12 is connected to the casing-carried terminal 621). When the mercury drop 68a closes the circuit at 61c, 520 in the mercury tube 60, the current flows through l2, 13, M, i2, 621), 62, 62c, 610, El to the other casing-carried binding post Blb which is provided with a ground wire connection 75 as indicated,

Having thus described my invention, what I claim as my invention is:

1. A thread defect indicator for incorporation with textile apparatus between the threadmanipulating means thereof and a thread supply means, said indicator comprising in combination a two-part casing includin interfitting mechanism-carrying and closure sections, a mounting means carried by said mechanism-carrying casing section and adapted for detachable engagement with a support, means for securing said casing sections together, laterally spaced exteriorally located thread guide elements carried by the mechanism-carrying casing section, a bearing sleeve projecting through and fixedly carried by one wall of the mechanismcarrying casing section, a rock shaft journalled in said bearing sleeve, a thread defect-actuated indicator normally engaging the thread between said guide elements, a mounting arm for said indicator, a bearing on the inner end of said arm and carried by said shaft, an adjustable collar on the inner end of said shaft and adapted to engage the inner end of said bearing sleeve whereby to cause the arm bearing to engage the outer end of said sleeve so as to eliminate axial movement of said shaft, a clip carried by said adjustable shaft collar, a mercury drop-incorporating switch detachably carried by said clip, a thread defect-indicating medium, an electrical control circuit therefor and including said mercury switch, and said collar bein adjustable on said shaft relatively of said indicator mounting arm whereby to close the said circuit throughsaid mercury switch when the indicator mounting arm is in one position and to open said circuit when the arm is in a different position.

2. A thread defect indicator for incorporation with textile apparatus between the threadmanipulating means thereof and a thread supply means, said indicator comprising in combination a two-part casing including interfitting mechanism-carrying and closure sections, a mounting means carried by said mechanism-carrying casing section and adapted for detachable engagement with a support, means for securing said casing sections together, laterally spaced exteriorally located thread guide elements carried by the mechanism-carrying casing section, a bearing sleeve projecting through and fixedly carried by one wall of the mechanism-carrying casing section, a rock shaft J'ournalled in said bearing sleeve, a thread defect-actuated indicator normally engaging the thread between said guide elements, a mounting arm for said indicator, a bearing on the inner end of said arm and carried by said shaft, an adjustable collar on the inner end of said shaft and adapted to engage the inner end of said bearing sleeve whereby to cause the arm bearing to engage the outer end of said sleeve so as to eliminate axial movement of said shaft, a mercury switch carried by said shaft collar, and an electrically operated thread defect-indicating medium controlled by said switch.

3. A thread defect indicator for incorporation with textile apparatus between the thread-manipulating means thereof and a thread supply means, said indicator comprising in combination a two-part casing including interfitting mechanism-carrying and closure sections, a mounting means carried by said mechanism-carrying casing section and adapted for detachable engagement with a support, means for securing said casing sections together, laterally spaced exteriorally located thread guide elements carried by the mechanism-carrying casing section, a bearing sleeve projecting through and fixedly carried by one wall of the mechanism-carrying casing section, a rock shaft journalled in said bearing sleeve, a thread defect-actuated indicator normally engaging the thread between said guide elements, a mounting arm for said indicator, a bearing on the inner end of said arm and carried by said shaft, an adjustable collar on the inner end said shaft and adapted to engage the inner end of said bearing sleeve whereby to cause the arm bearing to engage the outer end of said sleeve so as to eliminate axial movement of said shaft, a mercury switch carried by said shaft collar, an electrically operated thread defectindicating medium controlled by said switch, an exterior stop projecting from the bearing sleevecarried wall of the mechanism-carrying casing section, and yielding means normally actuating said indicator arm in a direction opposite to the direction of travel of the thread and against said stop.

AUSTIN E. STEVENS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Nar e Date 1,777,804 Miller Oct. 7, 1930 1,975,813 Weis Oct. 9, 1934 2,126,348 Rosenfeld Aug. 9, 1938 2,137,613 Hill Nov. 22, 1938 2,446,647 Frankwich Aug. 10, 1948 FOREIGN PATENTS Number Country Date 12,456 Great Britain of 1896 

